Ring sight eor mach



f 113 5651: OR 196869157 SR Oct 1928. 1,686,157

R. KAUCH ET AL RING SIGHT FOR MACHINE GUNS Filed v 1924 f x wi attozuu lETRlOAL lNSTRUMENTS.

Patented Oct. 2, 1928.

UNITED STATES ROBERT KAUCH AND CHARLES L PAULUS, OF DAYTON, OHIO.

RING SIGHT FOR MACHINE GUNS.

Application filed May 8, 1924. Serial No. 711,881.

This invention relates to improvements in ring sights for fixed or flexibly mounted machine guns used in aircraft combat.

The principal object is to provide a sight which is quickly adjustable and accurate in all stages of adjustment to facilitate the use of a machine gun in combat with different types of enemy aircraft attaining different speeds and with this object in view we have provided a plurality of sight rings of d1fferent sizes any one of which may be brought into use in an instant to direct the firing of a machine gun on any type of plane which may be encountered, the ring selected being marked for use in combat with planes attaining a certain speed and the matter of judging the speed of the hostile plane encountered being left to the pilot or gunner who is conversant with the speeds of different types of enemy planes and can therefore readily determine the speed of an approaching plane by merely observing its silhouette.

The invention is illustrated in the accompanying drawing, in which:

Fig. 1 is a view showing the application of the improved ring sight to a flexibly mounted aircraft machine gun.

Fig. 2 is a rear view of the ring sight removed from the gun and having one .of its several rings in firing position.

Fig. 3 is a side view of Fig. 2.

In aircraft combat a correction is made in the firing of machine guns to compensate for the speed of the enemy plane which may vary considerably as for example between one hundred and one hundred and fifty miles per hour. In flexibly mounted guns a correction is made by a wind vane bead sight for the speed of travel of the plane on which the gun is mounted. In the case of a fixed gun, such correction is of course unnecessary since the directing of the gun is coincident with the direction of flight of the plane. Ring sights have been used in combination with the front and rear sights of the gun to determine the divergence in sighting necessary to hit a target flying across the path of the plane on which the gun is mounted. The present invention provides sight rings of different size to enable accurate firing and thus make the gun effective against planes attaining various speeds. It is contemplated to use the sight rings with either flexibly mounted or fixed machine guns.

The ring sight as shown in Fig. 1 is mounted in the usual position of the rear sight behind a front sight 10, which in the present case is of the wind vane type, and comprises a bead 11 adjust-able to different positions with respect to the barrel depending on how the gun is directed with respect to the direction of flight of the plane on which it is mounted. A small fixed rear sight ring 12 is ordinarily provided in connection with the bead 11 and the gunner maintains his line of sight coincident with the ring 12 and the bead 11. The ring sight used in conjunction with the bead 11 and ring 12, of whatever form it may partake, is concentric with the ring 12 and the gunner, in directing the fire of the gun sights along the line of the bead 11 and ring 12 and determines the moment of opening fire by the position which the hostile plane assumes with respect to the rim of the ring concentric with the ringv 12. For example, in the case of a plane flying head-on, the firing will of course be done with the sighting coincident with the bead 11 and ring 12. In the case of a plane flying horizontally but diagonally across the path of flight firing should occur when the image of the enemy plane is approximately one-third of the way away from the center of the correcting ring. In the case of an enemy plane climbing or diving, corresponding corrections are made, the firing occurring sooner in the case of a diving than in the case of a climbing plane.

The present invention profvides a plurality of correcting sight rings 13 and 13 i of different sizes and inscribed with various rates of speed as indicated at 25 tobe used in combat with planes attaining different speeds. In the present case, five rings are provided of different sizes ranging for enemy speeds from one hundred and ten miles per hour to one hundred and fifty miles per hour. Each of the rings when brought from the horizontal to the vertical plane into fir ing position as shown in Fig. 2 is concentric with the ring 12. The shaft 14 of the sight ring 12 which is received in a socket 15 on the machine gun is hollow at its base to receive a coiled tension spring 16 which urges a plunger 17 downwardly against a pin 18 to tend yieldingly to move the latter toward an abutment 19 provided on the shaft 14. The pin 18 extends through elongated slots 20 in the walls of the hollow portion of the shaft 14 and has its opposite ends upset to rivet together the free ends of the rings 13 and 13' into a compact unit. The free ends of the rings 13 and 13' it will be noted from Fig. 3, are square so that the rings when selectively brought into firing position are vertical and are held in this position by the action of the spring 16 urging the ends thereof toward the abutment 19 by downward pressure upon the pin 18. The rings in reserve are held in horizontal inoperative relation similarly by the action of the spring 16.

It is apparent from the foregoing description that the use of a ring sight of the present form greatly facilitates the use of a machine gun in aircraft combat and that no matter which ring is brought into firing position, it is insured that a proper and accurate correction of the firing will be made. In certain types of ring sights used in the past, where it was sought to secure adjustability through various arrangements, a considerable degree of inaccuracy arose through not having proper concentricity of the adjusted ring with respect to the ring sight in all stages of adjustment. Furthermore, such devices proved unsatisfactory for the reason that an adjustment could not be made quickly and accurately. With the present device a pilot has only to observe an enemy plane and he can determine from its silhouette approximately its flying speed and has therefore only to bring the proper ring into firing position when he is ready for combat. Manifestly the simple operation of selecting and moving a ring into position consumes no appreciable time, and likewise a ring in operative position may be swung out of the way and replaced by another in an instant.

We claim 1. The combination with the rear sight of an aircraft machine gun comprising a normally vertical shaft having a sight piece on the upper end thereof, of a plurality of different sizes of sight rings for difierent enemy aircraft speeds, means mounting said rings to be swung into position selectively to concentric relation with said sight piece comprising a pin extending through a slot in the sight shaft having said rings pivoted thereon, means carried by said shaft and forming an abutment against which the pivoted portions of said rings engage, and spring means for yieldingly urging said pin toward said abutment.

2. A gun sight including a normally vertical shaft having a sight piece at the upper end thereof, a plurality of different sizes of rings pivotally carried by said shaft and adapted to be swung into position selectively to concentric relation with said sight piece, an abutment against which the pivoted portions of said rings engage and means for yieldingly retaining the pivoted portions of said rings in engagement with said abutment.

ROBERT KAUCH. CHARLES L. PAULUS. 

